Hommage à rené delépine à l'occasion de son départ à la retraite

A tribute to René Delépine on the occasion of his retirement. The career of René Delépine is reviewed on the occasion of his retirement. When he was a student, a meeting with Jean Feldmann led to a lifelong inclination towards phycology. Eventually appointed to the position of assistant professor at the University of Paris-VI (University Pierre-et-Marie-Curie), René Delépine worked and published primarily on the taxonomy of antarctic and subantarctic marine algae but he was also interested in seaweed aquaculture and utilizations. After organizing the national colloque ValVA (Valorisation des végétaux aquatiques), he became increasingly involved in the commercial application of seaweeds. His main activity, however, remained university teaching for which he was always enthusiastic, especially for teaching in the field and on the subject of the utilizations of algae. A list of his publications is given at the end of this article.     

Aspects originaux de la trichinose domestique à partir d'une infestation familiale découverte à Montréal

An outbreak of domestic trichinosis occurred in an Italian family living in Montreal. All patients had a fever, facial edema and extreme eosinophilia, and results of serologic tests were positive. Larvae of Trichinella spiralis were seen in a muscle biopsy from one of the patients. The discussion emphasizes some characteristic clinical, serologic and histopathological aspects.     

Imprégnations rapides à la Nigrosine applicables à la micro-ecologie des surfaces

Summary The ecology of primary biological coatings (fouling films) is an important aspect of benthic ecology in general. Life in a fouling film is, to a large extent, governed by physico-chemical laws of contact surfaces and surface tension. These laws apply also to the microecology of the mesopsammon and surface microplankton. The conditions common to these ecological situations enforce common characteristics, both morphological and physiological, upon the organisms which inhabit them. Many of these organisms are therefore subject to certain general techniques.Nigrosin is employed as an impregnating agent, and the speed of activity of the micelles of nigrosin is under the control of 1) the colloidal nature of the medium, and 2) alteration of cytoplasmic structures by the action of formalin added to the solution as a fixative.The stain blackens a variety of organites having a filamentous ultrastructure: cilia, flagella, trichocysts, rhabdites, cnidocysts, spiny processes of thecae and shells, capsules, cuticles and cuticular setae. The excess nigrosin surrounding the specimen may be removed completely by simple washing.Two particular situations are discussed: that of microbiocoenoses which develop at the point of contact of water and air (for example, bacterial films) and that of glass slides immersed in water with a view to studying the organisms which colonize surfaces in a particular habitat.The method has been applied also for studies of plankton in general, to demonstrate the liberation of flagellate bodies by certain algae, and for preparation of mounts of various organisms such as rotifers, gastrotrichs and nematodes. The method is very useful for quickly obtaining a comprehensive picture of the protozoan fauna in ecological studies.     

Paléopathologie : à propos de squelettes humains découverts à Poitiers (Vienne,France)

Palaeopathology: remarks about skeletons discovered in Poitiers (Vienne, France). Age, sex and stature of human fossils from a population decimated during an epidemic period are estimated. The prevalence of abnormalities and pathologies is compared with those of today’s population. Osteoarthritis is the most frequent pathology and this at different stage development. Osteoporosis and vertebrae compression are studied. The cases of important scoliosis are numerous. An abnormal vertebra is presented. A strange lesion on the ilium of the left coxa is discussed. Some hypotheses are formulated concerning the mode and the hygiene of life of this population. To cite this article: O. Boeuf, P. Alberti, C. R. Palevol 2 (2003) 169–180.     

Infections génitales à Chlamydiae et Mycoplasmes

Urogenital infections (chlamydiae and mycoplasms) are frequent, particulary in young, sexually active subjects. Tracking down these infections is difficult because there is often little or no clinical manifestation, and bacteriological exploration is difficult. It is nevertheless justified, because, first, the germs are sexually transmitted with possible genital after-effects, and secondly, treatment of them is simple since they are susceptible to antibiotics (cyclines, macrolides). This article, after a brief microbiological reminder, describes the clinical aspects of these ailments and usual treatment.     

Stratégies biologiques à l’heure de l’Assistance Médicale à la Procréation chez le blessé médullaire

Most men with spinal cord injury (SCI) men have fertility problems caused by anejaculation and decreased fertility of the ejaculate. There are two main causes for the impaired reproductive potential in SCI men: ejaculatory dysfunction and poor quality semen. However, current treatment techniques allow a large number of SCI males to achieve ejaculation (rectal electro-stimulation, penile vibrator stimulation). Firstly, masturbation and/or penile vibrator are used at home allowing the couple to perform insemination themselves. The semen of men with spinal cord injuries has commonly been characterised by small volume, abnormal count (low or high), decreased sperm mobility, increased formation of reactive oxygen species, sperm autoimmunity, necrospermia. This impairment is thought to be due to insufficient drainage, genitourinary infections and raised scrotal temperature. Testicular biopsy reveals varying degrees of tubule degeneration and decreased spermatogenetic activity. Semen could be used for various assisted reproductive technologies such as intrauterine insemination,in vitro fertilisation (IVF) and microinsemination (ICSI). The literature reports pregnancy rates by intrauterine insemination of about 15 to 20% per couple. Clinical pregnancy rates after IVF and ICSI techniques are 30% per cycle and these results are comparable to the clinical pregnancy rates when these techniques are performed for female infertility. However, semen must be frozen as soon as possible after the injury and the patient must be informed about the various available assisted reproductive technologies.     

La filiation et l'aide médicale à la procréation

Kinship following artificial insemination by unknown donor defines the child's mother and father as unknown. Although it could have been possible to construct this kinship on the model of adoption, the model adopted was that of blood and organ donation, which completely erases the donor's identity so that the recipient can take complete possession of the donated substance. But is gamete donation the same thing? Gamete donation concerns procreation and the parents' sexuality. Would it be possible to no longer consider the parents' sexuality to be exclusively reproductive sexuality allowing recognition of the progenitors alongside the mother and father?     

Cytochrome P450 et activation génétique — de la pharmacologie à l’élimination du cholestérol et à la régression de l’athérosclérose

Background

Lipoproteins are closely associated with the atherosclerotic vascular process. Elevated levels of highdensity lipoprotein cholesterol (HDL-C) and apolipoprotein AI (apo AI) in plasma indicate a low probability of coronary heart disease (CHD) together with enhanced longevity, and elevated levels of low-density lipoproteincholesterol (LDL-C) and apo B indicate an increased risk of CHD and death. Studies linking gene activation and the induction of cytochrome P450 with elevated plasma levels of apo AI and HDL-C and lowered plasma levels of LDL-C presented a new potential approach to prevent and treat atherosclerotic disease.

Objective and methods

This is a review aimed at clarifying the effects of P450-enzymes and gene activation on cholesterol homeostasis, the atherosclerotic vascular process, prevention and regression of atherosclerosis and the manifestation of atherosclerotic disease, particularly CHD, the leading cause of death in the world.

Results

P450-enzymes maintain cellular cholesterol homeostasis. They respond to cholesterol accumulation by enhancing the generation of hydroxycholesterols (oxysterols) and activating cholesterol-eliminating mechanisms. The CYP7A1, CYP27A1, CYP46A1 and CYP3A4 enzymes generate major oxysterols that enter the circulation. The oxysterols activate — via nuclear receptors — ATP-binding cassette (ABC) A1 and other genes, leading to the elimination of excess cholesterol and protecting arteries from atherosclerosis. Several drugs and nonpharmacologic compounds are ligands for the liver X receptor, pregnane X receptor and other receptors, activate P450 and other genes involved in cholesterol elimination, prevent or regress atherosclerosis and reduce cardiovascular events.

Conclusions

P450-enzymes are essential in the physiological maintenance of cholesterol balance. They activate mechanisms which eliminate excess cholesterol and counteract the atherosclerotic process. Several drugs and nonpharmacologic compounds induce P450 and other genes, prevent or regress atherosclerosis and reduce the occurrence of non-fatal and fatal CHD and other atherosclerotic diseases.     

Contribution à la systématique du genre Pichia

The presence of intracellular osidases, nitrite and nitrate reductases, vitamin requirements and GC content in the DNA, have been investigated for in 18 species of Pichia.According to their typical characters and their biocaracters, a pattern is suggested for the integration of these new species into the formerly existing groups of the genus Pichia. A new way of classifying the species of the genus Pichia is proposed.     

Endémie bilharzienne à Schistosoma mansoni à la vallée du Kou : caractérisation du système de transmission et impact socioéconomique

Schistosomiasis is one of the waterborne diseases which benefit from environmental and behavioral changes induced by the mobilization of surface water resources in Sahelian countries, such as Burkina Faso. Studies have established the existence of human schistosomiasis in the Kou valley, one of the oldest hydro-agricultural zones in the country. However, the role of population behavior in the transmission pattern of this disease and its socioeconomic impact in this valley are poorly understood. It is in response to these questions that this study was undertaken. The objectives of this study were to identify activities that exposed most of the Valley's population to infection by schistosomiasis, and to contribute knowledge on the consequences of this disease. The study was conducted in the cold dry season at the Kou Valley, located in the South Sudanese area of Burkina Faso. It has adopted the strategy of direct observation to examine host–parasites interactions. The study of the socioeconomic consequences of the infection has been first to identify subjects that actually carry the parasite by screening the population by the Kato–Katz method. These were then subjected to a questionnaire. Data were analyzed using Epi Info 6.4. This work has revealed six activities at risk of infection for the residents of the Valley with an increased risk of factor for rice farming, household activities and swimming. In view of these activities, women and young people seem to be most vulnerable to infection. This disease causes significant economic losses as a function of socio-professional categories of infected persons.     

Efficacité de la mémoire associative inhérente à la potentiation post-tétanique

An associative memory is modeled in networks of cells that are assumed to have the short-term plasticity of the neuromuscular junction of the frog. The data relating synaptic transmission efficiency and stimulation frequency for post-tetanic potentiation of the neuromuscular junction are represented by polynomial expansions. Simulation of storage and retrieval demonstrates that functional associative memory is feasible based on this particular synaptic plasticity. Retrieval reaches a maximum efficiency at a delay of three minutes after storage and is lost after about 9 min. The signal to noise ratio of the retrieved pattern drops steadily as additional associations are stored in memory but retrieval appears to be possible with up to four stored associations. Although the data are derived from synapses not normally proposed as a basis for memory functions, the results here will generalize to other synaptic junctions located more centrally that have similar characteristics. This simulation technique allows the efficiency of associative memory based on various types of synaptic plasticity to be evaluated.